Perinatal depression in a cohort study on Iranian women

BACKGROUND: Childbearing years in the women's life are associat ed with the highest risk of depression. In this stu dy depression in third trimester of pregnancy and afte r delivery was studied. Depressive symptom score an d the proportion of mothers above a threshold were compared to indic ate probable depressive disorder at each stage. METHODS: This prospective cohort study was conducted in rura l areas of Isfahan province of Iran from September 2007 to January 2008. Subjects were all in their third t rimester and followed up from the beginning of the study to 6-8 weeks postpartum. At all, 2156 pregnant women completed t h self report questionnaires but 258 were excluded because they were incomplete and final analysis was done with 18 98 samples. At the final stage the sample size was decreased to 1291. RESULTS: The prevalence of depression based on BDI score gre ater than 20 in last trimester of pregnancy, was 22 .8% and rate of depression based on EPD score greater t h n 12 between 6 to 8 weeks after delivery, was 26. 3%. Incidence of Post Partum Depression (PPD) in 6 to 8 weeks after delivery in those who were not clinically depressed during pregnancy was 20.1%. Results showed that history of dep ression, unplanned pregnancy, being housewife and h ving 3 or more children had significant relation with ante pa rtum depression. CONCLUSIONS: Two main risk factors for post partum depression ar e previous history of depression and depression during current pregnancy. It is important to assess the e variables during pregnancy in order to facil it te timely identification of women at risk.

omen in their childbearing ages are at higher risk of depression compared with any other time in their life. 1Longitudinal studies have shown that not only pregnancy does not protect women against the development of new onset major depression or relapse of existing major depressive illness, but also pregnancy and motherhood are periods of increased vulnerability to psychiatric disorders. 2ennett et al reported a depression prevalence, about 7.4%, 12.8% and 12% during the first, second and third trimesters. 3Josefsson et al studied depression during late pregnancy and reported prevalence of 17% that has been decreased to 13% by 6 to 8 weeks after delivery. 4Evans et al in a longitudinal study followed a group of women through pregnancy to the postpartum period and reported that prevalence of depression during pregnancy was nearly as the same as the results that were reported during the postpartum period. 1 In a meta-analysis by Gavin et al on major depression alone (major and minor depression), the combined point prevalence estimate ranged from 1.0-5.6%(6.5% to 12.9%) at different trimesters of pregnancy and months in the first postpartum year, the combined period prevalence shows that as many as 7.1% (19.2%) of women have a major depressive episode W (depressive episode) during the first 3 months postpartum; most of these episodes have onset following delivery. 57][8] Watson et al reported 23% of postnatal depressions were started during pregnancy. 9Depression during pregnancy has been associated with poor prenatal care, substance abuse, low birth weight, and preterm delivery. 10,11Psychiatric symptoms during pregnancy have physiological impacts on the fetus, which may explain some of these problems. 12tudies have shown that even when pregnant women who are at risk for depression are identified, they receive few treatments. 13mong the first researchers, who pointed out continuous process of depression through pregnancy into the postpartum period, were Gotlib et al and despite their observations, research during the past 25 years has focused on postpartum depression, so pregnancy-related depression has changed to a secondary issue. 14he DSM-IV-TR in postpartum-onset mood disorders diagnostic criteria, does not refer to depression during pregnancy. 15epression during pregnancy has changed to an important issue during the last 4 years in the medical literature.This may be due to increase in psychiatric referrals of depressed pregnant women, patients' increasing willingness to report symptoms to their primary caregivers or an increased awareness among physicians about the importance of depression during pregnancy for fetus development.This fact that undiagnosed and untreated depression in pregnant women persists throughout pregnancy and the postpartum period, has been caught widespread attention today. 1,4,14,16n this study depression in third trimester of pregnancy and after delivery was studied using prospectively gathered data from a cohort of 1898 women.Depressive symptom score and the proportion of mothers above a threshold were compared to indicate probable depressive disorder at each stage.

Methods
This prospective cohort study was conducted in rural areas of Isfahan province (with varied geographical, cultural and socio-economical properties) in central part of Iran.The health centers in the rural areas are responsible for providing health care services.They are supported by the Vice-Chancellor for Health of Isfahan University of Medical Sciences.
Resident health-care workers (Behvarz) in the village health centers (Health Homes) provide widespread primary health care.They also assist the visiting team of general practitioners (GP) and mental health professionals to conduct periodic visits in rural areas.
The primary health care program covers all residents of the villages in Iran.The data collection system in Health Home is based on uncomputerized records of all family characteristics including pregnant and child bearing women.
The Isfahan University of Medical Sciences ethics committee approved the design of the study.
In this study all villages were selected from whole area, for full coverage of different geographical and socio-economical participants.
Participants were all rural pregnant women in Isfahan province who were in their third trimester of pregnancy.Subjects were followed up from the beginning of the study to 6-8 weeks postpartum.About 3000 eligible pregnant women were recruited in this study based on primary information from the Vice-Chancellor for Health of Isfahan University of Medical Sciences.
Of them, 425 women were excluded because of literacy problems and the rest invited to participate; 2156 pregnant women agreed and completed the self administrator questionnaires.Of all, 258 questionnaires were excluded because they were incomplete and final analysis was done on 1898 samples.The sample size in the final stage of assessment (6-8 weeks postpartum) decreased to 1291 women.
This cohort study was carried out jointly between the Behavioral Sciences Research Center (BSRC) and The Vice-Chancellor for Health of Isfahan University of Medical Sciences.Mental health professionals in local departments of the Vice-Chancellor for Health of Isfahan University supervised the data collection as well as training the health-care workers (Behvarz) in all aspects of the study including its objectives and design.Health-care workers contacted all eligible women and requested them to attend at the Health Home at determined dates to complete the self-report questionnaires.Participant who were unable to attend, were assessed at their home.The completed questionnaires were gathered and then referred to mental health professionals in local departments by health-care workers.Mental health workers followed up women who were found to be severely depressed or suicidal at the assessment to ascertain the need for further management.The first questionnaire covered socio-demographic information (age, number of children, occupation, history of antidepressant use, attitude to pregnancy and past history of abortion) and the other ones were Persian version of Beck Depressive Inventory-II (BDI-II) and Edinburgh Postnatal Depression Scale (EPDS).
Depression during third trimester of pregnancy and 6-8 weeks postpartum was assessed using the Persian version of Beck Depression Inventory (BDI-II) 17 and Persian version of Edinburgh Postnatal Depression Scale (EPDS). 18DI is a 21-item scale with a four-point scale that ranges from 0 to 3 score; it is a selfadministered scale that takes 5 to 10 minutes to complete.Depression severity of each respondent, is the sum of the score on each item, ranging from 0 to 63 score.The average internal-consistency of the total scores is 0.86 for psychiatric patients and 0.81 for normal adults.The average correlation of the BDI total scores with clinical ratings of depression was greater than 0.90 for the both psychiatric patients and normal adults.Based on the obtained score, the severity of possible depression was assigned as follow: 0-9 (no depression), 10-16 (mild depression), 17-29 (moderate depression) and 30-63 (sever depression).Cut-off for depression screening in the general population is plus 21 for clinical depression score. 19,20he EPDS is a 10-items scale focuses on the cognitive and affective features of depression rather than somatic symptoms.It is the only self-report scale that has been validated for use in pregnancy and postnatal period. 21This scale itself cannot confirm a diagnosis of depression; however, a score above 12 is widely used to indicate probable depressive disorder.Validation of the EPDS showed that all women with diagnosis of major depression on interview had scored above 12 on the scale.Use of this threshold gave an overall sensitivity of 86% and specificity of 78% for all forms of depression. 22

Data Analysis
Data were analyzed using SPSS v.15.To demonstrate the initial results, univariate odds ratios (ORs) with 95% confidence intervals (CIs) were conducted for demographic variables and psychosocial risk factors of perinatal depression.A multiple logistic regression analysis was executed to detect prenatal and postpartum depression as the dependent variables and risk factors such as number of children, occupation, history of depression, attitude to pregnancy, mother's age, PICCA severity, history of abortion, neonatal hospital admissions and mother's refer to psychiatrist as independent variables based on the ORs with 95% confidence intervals (CIs).

Results
Of 1898 eligible pregnant women 1684 (88.7%) completed BDI-II during pregnancy and also 1291 (68%) of the total eligible pregnant women completed a postnatal EPDS included 1168 of them completed BDI-II plus 123 of noncompleted BDI-II.Point prevalence of depressed pregnant women (clinical depression) based on BDI score greater than 20 in last trimester of pregnancy was 22.8% (384/1684).However, postnatal response rate of depression based on EPD score greater than 12 between 6 to 8 weeks after delivery was 26.3% JRMS/ January & February 2010; Vol 15, No 1.Figure1.Overview of data collected from a total of 1898 available antenatal women in last trimester of pregnancy.EPDS were taken from 6 to 8 weeks after delivery in 1291 postnatal.
(340/1291).Incidence of (Post Partum Depression) PPD based on EPDS using cut-off > 12 between 6 to 8 weeks after delivery in those who were not clinically depressed during pregnancy (true definition of postpartum depression based on DSM-IV-TR) was 20.1% (183/910).Prevalence of depression based on EPDS > 12 between 6 to 8 weeks after delivery in those that were clinically depressed during pregnancy based on BDI > 20 was, 49.6% (128/258) and 51.4% of them recovered from depression after delivery (Figure 1).
The binary outcomes were BDI score and EPDS (Yes versus No) using cut-off > 20 and > 12, respectively.Logistic regression models were conducted for each explanatory variables and univariate odds ratios (ORs) with 95% confidence intervals (CIs) with respect of Beckscore in last trimester of pregnancy and EPDS in 6-8 weeks after delivery (Table 1).Some variables were categorized or reduced coding to obtain simple ORs.
Table 2 shows proportion and univariate odds ratios (ORs) with 95% confidence intervals (CIs) of depression for variables with respect of EPDS > 12 with score above or below the BDI cut-off at screening in 6-8 weeks after delivery.
Multiple logistic regressions were conducted for variables that were included in ta-bles 1 and 2 separately.The stepwise section process yielded a model with variables such as child number, occupation, history of depression, attitude to pregnancy, and mother's age using Beck-score in last trimester of pregnancy (Table 3).The results revealed that some variables such as history of depression, pregnant mother less than 25 years of age, being house wife and undesired pregnancy were important risk factors for perinatal depression.
There were 1143 postnatal EPDS scores that yielded a model with variables such as Beck score, history of depression, and mother's age using EPDS in 6-8 weeks after delivery (Table 4).

Discussion
It was found that postnatal depression (during 6-8 weeks after delivery) had higher prevalence, than prenatal depression (during third trimester).However these data may suggest that depression is more likely after childbirth than pregnancy, on the other hand this difference may be related to different depression assessment scale or time table of depression assessment during pregnancy and after delivery in this study.
There is prominent evidence against this concept that pregnancy protects patients from mental illness.Prevalence of depression during pregnancy estimated from 7-15% in developed countries 1,23 to 19-25% in economically underdeveloped countries. 2,23However depression prevalence is about 10% during the postpartum period and 7% after perinatal period. 1 Evidence based studies suggest that PPD may be a part of a continuous process, with onset during pregnancy. 14,16,24Although some of the present results are in coordination with these findings but postpartum depression incidence of 20.1% in those that were not depressed during the last trimester of pregnancy and recovery of 51.4% depressed pregnant women after delivery, are noticeable findings which suggest that PPD and depression during pregnancy may be separate entities.
Results of this study revealed that depression has a high prevalence during pregnancy and postpartum periods and about 50% of women that were depressed during pregnancy also remained depressed after delivery but the other 50% recovered from depression that shows controversial nature of relationship between prenatal and postnatal depression.In regard to studied variables, there were no significant differences between those remained depressed after delivery and those recovered from depression.][31] Based on a multiple logistic regression (Table 3) it was also found that history of depression, unplanned pregnancy, being housewife (a probable indicator of low education and poverty) and having 3 or more children were variables with significant relation to ante partum depression.Past history of depression has been consistently found to be one of the strong risk factors for PPD 25,32,33 and women with a history of mood disorder have a 30% chance of developing PPD 34 while one study reported that 78.3% of the women with PPD had a past and/or family history of depression. 35

Table 1 .
Univariate odds ratios (ORs) with 95% confidence intervals (CIs) of depression for variables in respect of Beck-score in last trimester of pregnancy and Edinburgh Postnatal Depression score(EPDS) in 6-8 weeks after delivery

Table 2 .
Proportion and univariate odds ratios (ORs) with 95% confidence intervals (CIs) of depression for variables in respect of Edinburgh Postnatal Depression score (EPDS) > 12 with Beckscore < 21 or Beck-score > 20 in 6-8 weeks after delivery

Table 3 .
Adjusted odds ratios (ORs) with 95% confidence interval (CIs) from multiple logistic regression model based on Beck-score>20 in last trimester of pregnancy (n = 1654)